Apparatus and method for monitoring a blocking body within an oil-well structure

ABSTRACT

A detection system for detecting when a blocking body has passed through a location within a well. The detection system includes a blocking body that is introducible into the well and is operatively configured to produce a detectable signal, and a detection tool that is configured to detect the detectable signal and to generate an output signal that indicates a detectable event.

TECHNICAL FIELD

The present disclosure relates to oil and/or gas wells. In particular the present disclosure relates to a method and an apparatus for detecting and/or monitoring an object within a well structure.

BACKGROUND

An oil and/or gas well may be formed by an outer casing located within a wellbore. The outer casing may optionally be secured within the wellbore by cement. The well may then include a tool or production string therein for working or producing from the well. During various procedures within the well, the well structure may utilize blocking bodies, such as balls, to engage and activate internal valves or to seal off ball-seats for isolating certain intervals or zones within the well. Isolating intervals or zones of the well is useful during hydraulic fracturing (fracking) operations and the like. One disadvantage of such blocking bodies is that the equipment utilized to introduce the blocking bodies by injecting, dropping or launching the blocking bodies into the well may be unreliable. This may cause uncertainty as to the number of the blocking bodies that are introduced and/or the timing of such introductions of the blocking body into the well. Ultimately, the user may not be certain as to the number or identification of which valves or ball seats within the well are activated by the introduced blocking bodies.

A known method to determine if a blocking body has been dropped is to watch the pressure within the well for a spike. The pressure spike may indicate that the blocking body has engaged in a valve within the well. However, such a method relies on indirect measurements of a blocking body's location and such a method may not provide a definitive answer as to whether a dropped blocking-body has been introduced into a well and engaged a valve within the well. Such a method also does not provide a definitive answer as to any particular valve that the blocking body may engaged. Such a method is also susceptible to operator error for example, if a brief pressure spike is missed then that may result in a false-negative when a ball has been introduced into the well.

SUMMARY

Some embodiments of the present disclosure relate to a system for monitoring blocking bodies that are introduced into a well. The system comprises a detection tool and at least one blocking body that is capable of generating a detectable signal. The detectable signal can be detected by the detection tool when the blocking body passes through a predetermined portion of the well. When the detection tool detects the detectable signal, the detecting tool generates an output signal that indicates that a detection event has occurred and the blocking body has approached, moved through and moved away from predetermined portion of the well.

In some embodiments of the present disclosure the detection tool utilizes one or more sensors for detecting the detectable signal. For example, if the detectable signal is a perturbation of a magnetic field, then the detection tool utilizes one or more magnetic sensors for detecting perturbations in the magnetic field. In other examples, the detectable signal may be another form of electromagnetic signals, such as a radio signal. The radio signal may be generated at a specific frequency and the one or more sensors of the detection tool are radio-frequency sensors. In some embodiments of the present disclosure the at least one blocking body comprises a radio frequency identification (RFID) member and when the RFID member approaches, moves through or moves away from the detecting tool, the one or more radio-frequency sensors can generate an output signal that indicates a detection event.

Some embodiments of the present disclosure relate to a detection system for detecting when a blocking body has passed through a location within a well. The detection system comprises a blocking body and a detection tool. The blocking body can be introduced into the well and is operatively configured to produce a detectable signal. The detection tool is configured to detect the detectable signal and to generate an output signal that indicates a detectable event.

In some embodiments of the present disclosure at least a portion of the blocking body comprises a magnetic material. In these embodiments, the detection tool also generates a magnetic field and comprises at least one sensor that can detect perturbations in the magnetic field that are caused by the blocking body approaching, moving through or moving away from the detection tool.

In some embodiments of the present disclosure, the blocking body comprises a radio frequency identification (RFID) tag that generates a radio signal and the detection tool comprises at least one sensor that can detect the radio signal.

Further embodiments of the present disclosure relate to a method for detecting a blocking body within a well. The method comprises the steps of configuring the blocking body to generate a detectable signal; configuring at least a portion of the well to detect the detectable signal; and creating an output signal that identifies when the detectable signal is detected.

In some embodiments of the present disclosure the detectable signal is a perturbation of a magnetic field. In some embodiments of the present disclosure the detectable signal is generated by an RFID tag and the at least a portion of the well can detect a radio signal generated by the RFID tag.

Without being bound by any particular theory, embodiments of the present disclosure allow a user to directly detect when a blocking body has passed through a predetermined portion of a well and in some embodiments when blocking bodies have passed through the predetermined portion of the well. This allows the user to know how many blocking bodies have been introduced into a well by relying on direct measurements of blocking bodies relative to the detection tool.

According to one aspect, there is disclosed a detection system for detecting when a blocking body has passed through a location within a well. The detection system comprises: (a) a blocking body that is introducible into the well and is operatively configured to produce a detectable signal; and (b) a detection tool that is configured to detect the detectable signal and to generate an output signal that indicates a detectable event.

In some embodiments, at last a portion of the blocking body comprises a magnetic material and the detection tool generates a magnetic field and comprises at least one sensor that can detect perturbations in the magnetic field caused by the blocking body approaching, moving through or moving away from the detection tool.

In some embodiments, the detection tool comprises a tubular body and two or more clamp pieces removably coupled about the tubular body, and wherein the two or more clamp pieces generate said magnetic field.

In some embodiments, the at least one sensor is coupled to the two or more clamp pieces.

In some embodiments, the detection tool further comprises at least one actuator coupled to the two or more clamp pieces for configuring the two or more clamp pieces to be away from the tubular body in an open condition or to be about the tubular body in a closed condition.

In some embodiments, the blocking body comprises a radio frequency identification (RFID) tag that generates a radio signal and the detection tool comprises at least one sensor that can detect the radio signal.

In some embodiments, the detection system further comprises a display for receiving and displaying the output signal from the detection tool.

According to one aspect, there is provided a method for detecting a blocking body within a well. The method comprises steps of: (a) configuring the blocking body to generate a detectable signal; (b) configuring at least a portion of the well to detect the detectable signal; and (c) creating an output signal that identifies when the detectable signal is detected.

In some embodiments, the detectable signal is a perturbation of a magnetic field.

In some embodiments, the detectable signal is generated by an RFID tag and the at least a portion of the well can detect a radio signal generated by the RFID tag.

In some embodiments, the RFID tag comprises a unique identifier, and wherein the output signal comprises said unique identifier.

BRIEF DESCRIPTION OF THE DRAWINGS

In drawings which illustrate embodiments of the present disclosure wherein similar characters of reference denote corresponding parts in each view;

FIG. 1 is a cross-sectional view of the top end of a wellbore having an outer casing and a production string located therein with one embodiment of a detection tool according to the present disclosure;

FIG. 2 is an isometric view of one embodiment of a detection tool according to the present disclosure;

FIG. 3 is a side-elevation, mid-line cross-sectional view of the detection tool shown in FIG. 2;

FIG. 4 is a top-plan, cross-sectional view of the apparatus of FIG. 2.

FIG. 5 is an illustration of one example of a display output showing voltage produced over time by a sensor of the apparatus of FIG. 2 as a blocking body according to the present disclosure passes therepast;

FIG. 6 is an isometric view of another detection tool according to embodiments of the present disclosure;

FIG. 7 is a side elevation view of another detection tool according to embodiments of the present disclosure;

FIG. 8 is a top-plan, cross-sectional view of a blocking body in use with a detection tool according to embodiments of the present disclosure;

FIG. 9 is a cross-sectional view of a sensor assembly according to embodiments of the present disclosure;

FIG. 10 shows mid-line, cross-sectional views of a blocking body, wherein in FIG. 10A the blocking body comprises a shell, and in FIG. 10B the blocking body comprises a core;

FIG. 11 is a side-elevation, mid-line cross-sectional view of a detection tool, according to some alternative embodiments of the present disclosure;

FIG. 12 is a side-elevation, mid-line cross-sectional view of a detection tool having a detection clamp, according to yet some alternative embodiments of the present disclosure;

FIG. 13 is a side-elevation, mid-line cross-sectional view of a detection tool having a detection clamp, according to still some alternative embodiments of the present disclosure;

FIG. 14 is an isometric view of a detection tool having a detection clamp having a detection clamp, according to some alternative embodiments of the present disclosure;

FIG. 15 is an isometric view of a detection tool having a detection clamp, according to yet some alternative embodiments of the present disclosure, wherein detection clamp is configured in an open condition; and

FIG. 16 is an isometric view of the detection tool shown in FIG. 15, wherein detection clamp is configured in a closed condition.

DETAILED DESCRIPTION

FIG. 1 shows a non-limiting example of a well assembly 10 located within a well bore 8 of a geological formation 6. While the geological formation 6 is shown at the surface where the well assembly 10 is positioned, it is understood that the geological formation 6 may be continuous with the surface at the position of the well assembly 10, or not. The well assembly 10 includes a well casing 12 having a top flange 14 which is securable to a pipe ram 16 or any other desired components that are employed at well sites. It will be appreciated that a detection tool 20 according to the present disclosure may be located at any location within the well assembly 10, such as, by way of non-limiting example, within or adjacent a riser, adjacent a frack-ball launcher (not shown), adjacent a blowout preventer (BOP) or at any other position within the well apparatus 10. It will be appreciated by those skilled in the art that only a single pipe ram 16 as an example of a well assembly 10 component is illustrated in FIG. 1 for the sake of clarity. It will be appreciated that many well assemblies 10 can include more than one of such component and other components. As illustrated in FIG. 1, the well assembly 10 includes the detection tool 20 for detecting a signal generated by a blocking body 15 (shown in FIG. 8) with one or more further components 18 of the well assembly 10 located thereabove. A blocking body 15 may pass through the detection device 20 by being introduced into, for example dropped or actively pushed through, a portion of the well assembly 10 above the detection tool 20.

In some embodiments of the present disclosure, the detection tool 20 is substantially the same as the device described in U.S. Pat. No. 9,097,813 , the entire disclosure of which is incorporated herein by reference. In these embodiments, the detection tool 20 is configured to detect a perturbation in a magnetic field that is caused by one or more blocking bodies 15 approaching, passing through and moving away from the detection tool 20.

FIG. 1 shows the well assembly 10 as including a production or tubing string 115 that is located within the well assembly 10. The string 115 also includes one more regions of a larger outer diameter 117, for example a tool joint, a downhole tool or otherwise. It will be appreciated by one skilled in the art that the one or more blocking bodies 15 may be introduced into the tubing string 115 above the detection tool 20 and the one or more blocking bodies 15 can travel down the tubing string 115 to engage a downhole element (not shown). Examples of downhole elements include but are not limited to: sliding sleeve, seated ball valves and the like. Alternatively, the tubing string 115 may not be present as a component of the well assembly 10 and the one or more blocking bodies 15 may be introduced into the well assembly 10 above the detection tool 20 and the one or more blocking bodies 15 may travel down a portion of the well bore 8 to engage a downhole element.

In some embodiments of the present disclosure, the detection device 20 is configured to detect the signal generated by the blocking body 15 and the detection device 20 is also configured to generate an output signal that is communicated to a computer 88 and/or display 89. The computer 88 and/or display 89 indicate to a user that the blocking body 15 is approaching, moving through or moving away from the detection tool 20 to permit the user to determine when a blocking body 15 has passed through the detection tool 20 and into the well bore 8 below.

With reference to FIG. 2, the detection tool 20 comprises a body 22 having at least one magnetic stack 70 and at least one sensor stack 80 extending away from the body 22. The body 22 comprises at least one tubular or ring-shaped body 22 section. FIG. 2 shows an upper section or flange 28 and a lower section or flange 30. Each body 22 section 28, 30 has inner and outer surfaces, 24 and 26, respectively and extending between top and bottom surfaces, 27 and 29, respectively (shown only on the upper body 22 section 28). As illustrated in FIG. 2, the inner and outer surfaces 24 and 26 are substantially cylindrical about a central axis 32 of the body 22. The inner surface 24 defines a central passage 34 extending therethrough which may be sized and shaped to correspond to the interior of the casing 12. As illustrated in FIG. 2 and FIG. 3, the top and bottom surfaces are substantially planar along a plane normal to the axis 32 and may optionally include a seal groove 36 extending annularly therearound for receiving a seal as are commonly known in the art.

The body 22 includes at least one bolt hole 35 that extends therethrough between the top and bottom surfaces 27 and 29 along an axis that is substantially parallel to the central axis 32. The bolt holes 35 are utilized to pass fasteners, such as bolts 38 as illustrated in FIG. 1 therethrough to secure the body 22 inline to the other components of the well assembly 10 according to known methods in the art.

The body 22 includes at least one magnetic stack 70 and at least one sensor stack 80 as will be more fully described below. Optionally each of the stacks 70 and 80 may be contained within a housing, such as, by way of non-limiting example, a sleeve 40 extending from the outer surface of the body 22 (as shown in FIG. 2 and FIG. 3) between the upper and lower bodies 28, 30.

The body 22 may have any distance between the upper and lower sections 28, 30 as is necessary to accommodate the stacks 70, 80. By way of non-limiting example the body 22 may have a distance between the upper and lower sections 28, 30 of between 3.5 and 24 inches (89 and 610 mm) with a thickness of approximately 4 inches (102 mm) having been found to be particularly useful. Additionally, the body 22 will be selected to have an inner diameter of the inner surface 24 to correspond to the inner passage of the casing 12. In practice it has been found that an outer diameter of between 4 and 12 inches (102 and 305 mm) larger than the inner diameter has been useful. The body 22 may be formed of a non-magnetic material, such as, by way of non-limiting example a nickel-chromium based alloy, such as Inconel® manufactured by Special Metals Corporation. It will also be appreciated that other materials may be useful as well, such as, by way of non-limiting example duplex and super duplex stainless steels provided they do not interfere with the sensor operation as described below.

Optionally, the body 22 may be formed as a hub clamp wherein the upper and lower sections 28, 30 comprise clamping bodies adapted to clamp adjacent pipes as illustrated in FIG. 6 and as are commonly known. In operation, the top and bottom flanges 28 and 30 may be secured to such additional structures through the use of bolts or the like as is commonly known. Optionally, the body 22 may be formed as a hub clamp wherein the top and bottom flanges 28 and 30 may comprise clamping bodies adapted to clamp adjacent pipes as illustrated in FIG. 6.

As set out above, the body 22 may optionally include a plurality of sleeves 40 that are adapted to contain and protect the stacks 70 and 80 that extend radially from the outer surface 26 of the body 22. As illustrated in FIG. 2 through FIG. 4, the sleeves 40 may extend radially from the body 22. It will be appreciated that the stacks 70 and 80 may also extend from the tubular body 22 without such sleeves 40 therearound. As illustrated in FIG. 3, each of the sleeves 40 may be located at a position along the tubular body 22 so as to form a common plane 42 perpendicular to the central axis 32 of the apparatus. As illustrated in FIG. 7, the magnetic and sensor stacks 70 and 80 may also be arranged along more than one plane 42 a, 42 b and 42 c so as to form sensor locations enabling a user to track the progress of blocking bodies 15 through the detection tool 20.

The sleeves 40 comprise tubular members extending between first and second ends, 46 and 48, respectively, and having inner and outer surfaces, 50 and 52, respectively. The sleeves 40 may be formed of a substantially ferromagnetic material, such as steel so as to conduct magnetic flux as will be more fully described below. The sleeves 40 are selected to have a sufficient inner surface diameter sufficient to accommodate a magnetic stack 70 or a sensor stack 80 therein as more fully described below. By way of non-limiting example it has been found that a diameter of the inner surface of between 0.5 and 6 inches (13 and 152 mm) has been useful. The sleeve 40 may also have a length sufficient to receive the sensor and magnet stacks therein, such as by way of non-limiting example, between 0.5 and 6 inches (13 and 152 mm). Additionally, it will be appreciated that where other housing types are utilized, such housings may be formed of any suitable size to contain and protect the stacks 70, 80 from impacts or the like.

Turning now to the non-limiting examples of FIG. 3 and FIG. 4, the sleeves 40 are arranged around the body 22 along a common plane 42. The common plane 42 is perpendicular to the central axis 32 and may be located at any height along the body 22 such as by way of non-limiting example, midpoint therealong as illustrated in FIG. 3. As illustrated in FIG. 4, the sleeves 40 may be arranged around the tubular body 22 at regular intervals; however this may not be required. As illustrated herein, sleeves 40 are secured to the outer surface 26 of the tubular body 22 by using suitable means such as welding, gluing (e.g., using epoxy), and/or the like. The sleeves 40 contain therein at least one magnetic stack 70 and at least one sensor stack 80 wherein the magnetic stack 70 generates a magnetic field within the interior of the central passage 34 and the sensor stack 80 measures changes in this magnetic field in response to a blocking body 15 passing therethrough. In particular, the magnetic stacks 70 and sensor stacks 80 may be alternated around the tubular body 22 and it will therefore be appreciated that an even number of sleeves will be required. It will also be appreciated that other arrangements of magnetic and sensor stacks may be useful as well.

The magnetic stack 70 comprises at least one magnet 60 that is sized to be located within the sleeve 40. The magnets 60 are selected to generate strong magnetic fields. In particular, it has been found that rare earth magnets, such as, by way of non-limiting example, neodymium, samarium-cobalt or electromagnets. Optionally, the magnets 60 may also be nickel plated or otherwise coated for corrosion resistance.

The sensor stack 80 comprises a sensor 82 adapted to provide an output signal in response to the magnetic field in their proximity. By way of non-limiting example, the sensors 82 may comprise magnetic sensors, such as hall-effect sensors although it will be appreciated that other sensor types may be utilized as well. In particular it has been found that a Hall effects sensor, such as a model SS496A1sensor manufactured by Honeywell® has been particularly useful although it will be appreciated that other sensors will also be suitable. The sensors 82 are inserted into the sleeves 40 to be proximate to the first end 46 thereof and are retained within the sleeves 40 by any suitable means, such as, by way of non-limiting example, adhesives, threading, fasteners or the like. The sensors 82 may each include an output wire 86 that extends therefrom as illustrated in FIG. 1. The output wire 86 is wired or otherwise connected to a computer 88 which optionally outputs to a display 89 and is therefore operable to provide an output signal that indicates whether a detection event has occurred.

The sensor stack 80 may also optionally include a magnet 84 located at the second end 48 of the sleeve 40. The magnets 84 are selected to have strong magnetic fields. In particular, it has been found that rare earth magnets, such as, by way of non-limiting example, neodymium, samarium-cobalt or electromagnets. Optionally, the magnets 84 may also be nickel plated or otherwise coated for corrosion resistance. The magnets 84 are located at the second ends 48 of the sleeves 40 and retained in place by any suitable means, such as, by way of non-limiting example, adhesives, threading, fasteners or the like.

With reference to FIG. 5, the output 100 may display the voltage signal outputted by the one or more sensors 82 against time. During a first time period, the voltage signal will be at a first level, generally indicated at 102, while no blocking body 15 is near to passing through the detection tool 20. As the blocking body 15 approaches the detection tool 20, the voltage output of the sensors 82 will be increased, generally indicated by the slope between 102 and 104, due to the detection tool 20 detecting the detectable signal from the blocking body 15 within the central passage 34. After the blocking body 15 passes through the detection tool 20, the voltage will return to a lower level 106. In such a manner, the display 100 will indicate to an operator when the blocking body 15 has approached and passed through the detection tool 20.

In some embodiments of the present disclosure, the sensors 82 may be calibrated prior to operation by locating a magnetic body of known size and position within the central passage 34 and adjusting the readout for each sensor 82 a, 82 b and 82 c according to known methods. Optionally, a radio frequency emitter device may also be used to calibrate the radio frequency sensors within the detection tool 20. As illustrated in FIG. 8, a single set of 3 sensors 82 may be utilized to provide a location of the blocking body 15 as it passes through the detection tool 20. It will be appreciated, that additional sets of 3 or more sensors may also be provided to provide an additional measure of the position of the blocking body 15.

FIG. 9 provides a detailed cross-sectional view of one embodiment of the magnetic stack 70. The magnetic stack 70 may be located within a sleeve 40 which also includes an actuator 120 and an actuator shaft 122 extending from the actuator 120 to the magnetic stack 70. In operation, the actuator 120 may extend or retract the magnetic stack 70 into and out of engagement with the outer surface 26 of the tubular body 22. In the retracted position, the magnetic field produced by the magnetic stack 70 will be reduced thereby permitting any ferromagnetic particles that may be attracted thereto to be released from the interior of the central passage.

Turning now to FIG. 10A and FIG. 10B, the blocking body 15 is shown as a ball; however, the person skilled in the art will appreciate that the blocking body 15 may be any shape that will allow the blocking body 15 to be introduced into the well 8 and to move to engage a desired downhole element. Regardless of shape, at least a portion of the blocking body 15 may comprise a material that can perturb a magnetic field, for example a magnetic material. This magnetic material provides the blocking body 15 an operative configuration to create a detectable signal. For example, in some embodiments of the present disclosure, the blocking body 15 comprises a shell 17 as illustrated in FIG. 10A and the shell is at least partially made of a magnetic material. In other embodiments, the blocking body 15 may comprise a core 19 located therein and the core 19 is at least partially made up of a magnetic material. In some embodiments of the present disclosure, the blocking body 15 may include both the shell 17 and the core 19. In other embodiments, the entire blocking body 15 may be formed of a magnetic material. The magnetic material for the blocking body 15 may be selected from a group consisting of ferrous alloy such as, by way of non-limiting example, alloy steels, carbon steels or cast iron although it will be appreciated that other metals may be useful here as well, provided that they can perturb a magnetic field.

In some embodiments of the present disclosure, the blocking body 15 may comprise a radio frequency identification tag (RFID) and the RFID tag provides the blocking body 15 with an operative configuration to create the detectable signal. The detection tool 20 includes a sensor or reader that can detect when the radio signal—and therefore the blocking body 15—is approaching, passing through or moving away from the detection tool 20. In some embodiments of the present disclosure, the detection tool 20 comprises sensors that can detect perturbations in a magnetic field and/or sensors that can detect a radio signal generated by and RFID tag. In some embodiments, a plurality of blocking bodies 15 may be available for use. Each blocking body 15 comprises a RFID having a unique identifier for indicating the identity of the blocking body 15. When a block body 15 approaching, passing through or moving away from the detection tool 20, the detection tool 20 uses the sensor or reader to detect the unique identifier of the RFID of the blocking body 15 to determine which blocking body 15 is approaching, passing through or moving away from the detection tool 20.

Although in above embodiments, the sleeves 40 are secured to the outer surface 26 of the tubular body 22, in some alternative embodiments as shown in FIG. 11, the tubular body 22 comprises one or more blind bores 44 radially inwardly extending from the outer surface thereof into the tubular body 22 without penetrating the wall thereof. Each blind bore 44 at least partially receives a sleeve 40 and mounting it therein by suitable means such as threading, gluing and/or the like.

In some alternative embodiments as shown in FIG. 12, the detection tool 20 comprises a detection clamp 45 removably coupled to the tubular body 22. The detection clamp 45 comprises one or more blind bores 44 radially inwardly extending from the outer surface thereof into the detection clamp 45 the wall thereof. Each blind bore 44 at least partially receives a sleeve 40 and mounting it therein by suitable means such as threading, gluing and/or the like.

In some alternative embodiments as shown in FIG. 13, the detection tool 20 comprises a detection clamp 45 removably coupled to the tubular body 22. The detection clamp 45 comprises one or more bores 44 radially inwardly extending therethrough. Each bore 44 at least partially receives a sleeve 40 and mounting it therein by suitable means such as threading, gluing and/or the like.

In some alternative embodiments as shown in FIG. 14, the detection tool 20 comprises a detection clamp 45 having one or more bores sleeves 40 attached thereto as described above. In these embodiments, the detection clamp 45 comprises two clamp pieces 45A and 45B removably coupled to the tubular body 22 using suitable means such as bolts.

Those skilled in the art will appreciate that, during operation, metal filings and/or debris may be generated due to wearing of various metal components. The magnetic field associated with the detection tool 20 may trap the metal filings onto the inner surface of the central passage 34. To remove the trapped filings from the detection tool 20, in a cleaning process, an operator may periodically separate the two clamp pieces 45A and 45B and remove them from the tubular body 22. As the magnets 60 and 84 of the magnetic stacks 70 and the sensor stacks 80 are coupled to the clamp pieces 45A and 45B, the magnetic field thereof are thus removed from the tubular body 22 when the clamp pieces 45A and 45B are removed therefrom. The trapped filings on the inner surface of the central passage 34 thus fall off and are removed from the detection tool 20. After cleaning, the operator may then couple the two clamp pieces 45A and 45B back to the tubular body 22.

In some alternative embodiments as shown in FIGS. 15 and 16, the detection tool 20 comprises a clamp or ram 45 removably coupled to the tubular body 22. The detection clamp 45 comprises a base or anchor 132 for (removably or non-remobaly) mountable to the tubular body 22. Two clamp pieces 45A and 45B are rotatably coupled to the anchor 132 such that, when the anchor 132 is mounted to the tubular body 22, the two clamp pieces 45A and 45B may be rotated to a closed condition about the tubular body 22 as shown in FIG. 16, or rotated to an open condition away from the tubular body 22 as shown in FIG. 15. One or more bores sleeves 40 are attached to the two clamp pieces 45A and 45B as described above.

The detection clamp 45 also comprises one or more actuators 134 coupled to the two clamp pieces 45A and 45B for rotating the two clamp pieces 45A and 45B to the open or closed conditions. An electrical or hydraulic motor (not shown) is used for driving the one or more actuators 134 to rotate the two clamp pieces 45A and 45B. In operation, the motor may be programmed to periodically rotating the two clamp pieces 45A and 45B to the open condition away from the tubular body 22 to clean any filings trapped in the detection tool 20. After cleaning, the motor rotates the two clamp pieces 45A and 45B to the closed condition about the tubular body 22.

In some embodiments, the motor comprises a wired or wireless communication means for receiving commands from a control center (not shown). In operation, an operator in the control center may remotely command the motor to rotate the two clamp pieces 45A and 45B to the open condition away from the tubular body 22 to clean any filings trapped in the detection tool 20. After cleaning, the operator in the control center may command the motor to rotate the two clamp pieces 45A and 45B to the closed condition about the tubular body 22.

Although in above embodiments, the detection clamp 45 comprises two clamp pieces 45A and 45B, in some alternative embodiments the detection clamp 45 may comprise more than two clamp pieces.

Although in above embodiments, the sleeves 40 including the magnets 60 and 84 and the sensors 82 are coupled to the detection clamp 45, in some alternative embodiments, only the magnets 60 and 84 are coupled to the detection clamp 45 and the sensors 82 are directly coupled to the tubular body 22.

Although in above embodiments, the two or more clamp pieces 45A and 45B are roatably configurable to the open and closed conditions, in some alternative embodiments, the two or more clamp pieces 45A and 45B may be configurable to the open condition away from the tubular body 22 and the closed condition about the tubular body 22 by any other suitable means. For example, in some embodiments, the two or more clamp pieces 45A and 45B may be radially movable towards or away from the tubular body 22 by the actuation of one or more actuators 134 to be configured to the open and closed conditions, respectively. 

1. A detection system for detecting when a blocking body has passed through a location within a well, the detection system comprising: a. a blocking body that is introducible into the well and is operatively configured to produce a detectable signal; and b. a detection tool that is configured to detect the detectable signal and to generate an output signal that indicates a detectable event.
 2. The detection system of claim 1 wherein at last a portion of the blocking body comprises a magnetic material and the detection tool generates a magnetic field and comprises at least one sensor that can detect perturbations in the magnetic field caused by the blocking body approaching, moving through or moving away from the detection tool.
 3. The detection system of claim 2 wherein the detection tool comprises a tubular body and two or more clamp pieces removably coupled about the tubular body, and wherein the two or more clamp pieces generate said magnetic field.
 4. The detection system of claim 3 wherein the at least one sensor is coupled to the two or more clamp pieces.
 5. The detection system of claim 4 wherein the detection tool further comprises at least one actuator coupled to the two or more clamp pieces for configuring the two or more clamp pieces to be away from the tubular body in an open condition or to be about the tubular body in a closed condition.
 6. The detection system of claim 5 wherein the blocking body comprises a radio frequency identification (RFID) tag that generates a radio signal and the detection tool comprises at least one sensor that can detect the radio signal.
 7. The detection system of claim 6 further comprising a display for receiving and displaying the output signal from the detection tool.
 8. A method for detecting a blocking body within a well, the method comprising steps of: a. configuring the blocking body to generate a detectable signal; b. configuring at least a portion of the well to detect the detectable signal; and c. creating an output signal that identifies when the detectable signal is detected.
 9. The method of claim 8, wherein the detectable signal is a perturbation of a magnetic field.
 10. The method of claim 9 wherein the detectable signal is generated by an RFID tag and the at least a portion of the well can detect a radio signal generated by the RFID tag.
 11. The method of claim 10 wherein the RFID tag comprises a unique identifier, and wherein the output signal comprises said unique identifier. 